The present invention relates generally to manual automobile transmissions of the constant-meshed type with two parallel shafts and is more particularly concerned with improvements in the method for supporting a counter gear member mounted upon a counter shaft in meshed relationship with the speed change gears of the transmission.
In known constant-meshed manual transmission systems of the two-parallel shaft type, where the counter gears are adapted separately from the counter shaft, needle roller bearings are provided at both ends of the counter gear assembly in order to sustain a radial load. Thrust washers are provided between the counter gear assembly and the transmission casing in order to support the thrust load. Accordingly, in order to effect assembly of the counter shaft in a secure manner within a short period of time with the counter gears appropriately meshed with the speed change gears, it is necessary to utilize a dummy shaft in order to prevent dislocation of the needle roller bearings and thrust washers at both ends of the counter gear assembly. Additionally, it is found troublesome and time consuming to fit the counter shaft in position while drawing out the dummy shaft. Furthermore, since the load capacity of the thrust washer is rather small and seizing is likely to occur, an appropriate thrust clearance must be provided and much care must be exercised in the selection of the wall thickness. Also, a suitable detent or locking mechanism becomes necessary in such a device.
The present invention is aimed at eliminating the aforementioned disadvantages. To this end, the invention proposes means whereby the counter gear member may be supported at both its ends upon the counter shaft which is fixed in the transmission housing in order to overcome and avoid many of the problems encountered with prior art arrangements.